Full thread socket head cap screw – Determination of Tensile Strength Tests on Fastener Products

When the finished product of the full thread socket head cap screw is out, we will carry out the tensile test on the screw according to the customer’s request to ensure that the quality of the screw meets the customer’s requirements.

Fastener products suitable for tensile testing:

1. Bolts and screws with better head bearing capacity than threaded rods
2. The head bearing capacity is stronger than the screw and bolt of the threadless rod
3. No threaded rod diameter> or ≈
4. The nominal length of screws and bolts ≥ 2.5
5. Thread length b ≥ 2.0d
6. Bolted bolts b<2d
7. The total length of the stud is ≥3.0d

8.3mm ≤ d ≤ 39mm

9. All performance levels

Figure 1 Wedge pad for screw finished wedge load test

Test procedure for fully threaded hex socket head screws:

1. The full thread socket head cap screwused for testing shall be a fastener that has passed the inspection of size.
2. Screw the test piece into the internal thread clamp as shown in Figure 1. Thread effective threading length ≥. Length of unthreaded thread
3. According to the provisions of GB/T 228.1 tensile test, the separation rate of the test machine chuck should not exceed 25mm / min.
4. The tensile test should be continued until it breaks. Measure the ultimate tensile load.

Test results for full thread socket head cap screw:

According to the nominal stress cross-sectional area and the measured ultimate tensile force during the test, the tensile strength is calculated according to the following formula:

The sum of the test pieces shall comply with the standard and shall be broken within the length of the unthreaded thread or without the threaded rod.

If the fracture of the full threaded screw begins within the length of the unthreaded thread, it is allowed to extend or extend to the head to thread intersection or to the head before breaking.

If you want to customized full thread socket head cap screw, please send an email: annie.li@szsst88.com